Fiber optic cable assembly with integrated shuffle and fabrication method

ABSTRACT

A fiber optic cable assembly suitable for providing mesh connectivity includes a fiber shuffle region arranged between first and second cable assembly sections that each include multiple tubes each containing a group of optical fibers, with a jacket provided over one or both cable assembly sections. The fiber shuffle region may be compact in width and length, and integrated into a trunk cable. Optical fibers remain in sequential order in groups at ends of the cable assembly sections, where the fibers may be ribbonized and/or connectorized. A fabrication method for such a fiber optic cable assembly is also disclosed.

PRIORITY APPLICATION

This application is a continuation of International Application No.PCT/US20/30237, filed on Apr. 28, 2020, which claims the benefit ofpriority to U.S. application Ser. No. 16/419,571, filed on May 22, 2019,now U.S. Pat. No. 10,678,012, both applications being incorporatedherein by reference.

BACKGROUND

The disclosure relates generally to fiber optic cable assembliessuitable for making optical cross connections, in addition to methodsfor fabricating such assemblies.

Optical fibers are useful in a wide variety of applications, includingthe telecommunications industry for voice, video, and data transmission.In a telecommunications system that uses optical fibers, there aretypically many locations where fiber optic cables (which carry theoptical fibers) connect to equipment or other fiber optic cables.

FIG. 1 is a cross-sectional view of an exemplary coated optical fiber100 that includes a glass core 102, glass cladding 104 surrounding theglass core 102, and a multi-layer polymer coating 110 (including aninner primary coating layer 106 and an outer secondary coating layer108) surrounding the glass cladding 104. The inner primary coating layer106 may be configured to act as a shock absorber to minimize attenuationcaused by any micro-bending of the coated optical fiber 100. The outersecondary coating layer 108 may be configured to protect the innerprimary coating layer 106 against mechanical damage, and to act as abarrier to lateral forces. The outer diameter of the coated opticalfiber 100 may be about 200 μm, about 250 μm, or any other suitablevalue. Optionally, an ink layer (e.g., having a thickness of about 5 μm)may be arranged over the outer secondary coating layer 108 of the coatedoptical fiber 100 to color the fiber (e.g., as is commonly used inribbonized fibers), or a coloring agent may be mixed with the coatingmaterial that forms the outer secondary coating layer 108. An additionalcovering (not shown), which may be embodied in a tight buffer layer or aloose tube (also known as a furcation tube or fanout tube), may beapplied to the coated optical fiber 100 to provide additional protectionand allow for easier handling, wherein the resulting buffered orfurcated optical fibers typically have an outer diameter of about 900μm.

Groups of coated optical fibers (e.g. four, eight, twelve, twenty-four,or more) optical fibers) may be held together using a matrix material orintermittent inter-fiber binders (“spiderwebs”) to form “optical fiberribbons” or “ribbonized optical fibers” to facilitate packaging withincables. For example, optical fiber ribbons are widely used in cables forhigh-capacity transmission systems. Some modern cables in large-scaledata centers or fiber-to-the-home networks may contain up to 3,456optical fibers, and cables having even higher optical fiber counts areunder development. Optical fibers that form a ribbon are arranged inparallel in a linear (i.e., one-dimensional) array, with each fibertypically having a different color or marking scheme for ease ofidentification. FIG. 2 provides a cross-sectional view of a multi-fiberribbon 112, which includes twelve optical fibers 114A-114L and a matrix116 encapsulating the optical fibers 114A-114L. The optical fibers114A-114L are substantially aligned with one another in a generallyparallel configuration, preferably with an angular deviation of no morethan one degree from true parallel at any position. Although twelveoptical fibers 114A-114L are shown in the ribbon 112, it is to beappreciated that any suitable number of multiple fibers (but preferablyat least four fibers) may be employed to form optical fiber ribbonssuitable for a particular use.

Optical communication systems utilizing fiber optic cables are asubstantial and fast-growing constituent of communication networks, dueto the low signal losses and large transmission bandwidth inherent tooptical fibers. Hyperscale data centers have emerged in recent years tosupport high bandwidth communications.

Hyperscale datacenters have been converging into leaf-spine architecturewith low oversubscription (wherein oversubscription refers to thepractice of connecting multiple devices to the same switch port tooptimize switch port utilization). Low oversubscription is critical tosupport diverse applications such as social media, web searching, cloudservices, and artificial intelligence/machine leaning/deep learning.

Leaf-spine network architecture is a two-layer network topology that isuseful for datacenters that experience more east-west network trafficthan north-south traffic. Leaf-spine networks utilize a leaf layer and aspine layer. The spine layer is made up of switches that performrouting, working as the network backbone. The leaf layer involves accessswitches that connect to endpoints. In leaf-spine architecture, everyleaf switch is interconnected with every spine switch, permitting anyserver to communicate with any other server using no more than oneinterconnection switch path between any two leaf switches.

FIG. 3 shows an example of a non-blocking leaf-spine switch network 120in a full mesh configuration, where each leaf switch 124 has a portconnected to a port of each spine switch 122. In the particularimplementation of FIG. 3, twelve spine switches 122 and twelve leafswitches 124 are provided, with each spine switch 122 and each leafswitch 124 having twelve ports, for a total of one hundred forty-fourlinks that are provided by optical fibers 126. If each link includes aSmall Form Pluggable (SFP) duplex fiber transceiver (having a dedicatedtransmit (TX) fiber and a dedicated receive (RX) fiber), then the numberof optical fibers 126 connecting the spine switches 122 and leafswitches 124 would be increased to two hundred eighty-eight.

A base unit of mesh connectivity can be scaled to interconnect a largernumber of switches, limited only by the port count of the switches. FIG.4 shows a large number of spine switches 132 and leaf switches 134 thatare organized in groups (e.g., spine switch groups 133A-133D and leafswitch groups 135A-135H, respectively) providing a super-mesh switchnetwork configuration 130, with a multitude of optical fiber jumpers 136providing full mesh connectivity between all the spine switches 132 andleaf switches 134. In this example, ninety-six leaf switches 134 areconnectible to forty-eight spine switches 132 in a full mesh networkusing thirty-two base units of mesh connectivity, with each base unithaving one hundred forty-four links. As will be apparent, any suitablenumber of switches can be chosen as the base unit in leaf-spine networksproviding full mesh connectivity.

In typical practice, spine switches and leaf switches are physicallylocated in different areas of a datacenter building. Structured cablingis essential to fiber management. Traditional straight trunk cables maybe used to bring the fibers close to the spine switches, and thensubunits are broken out to connect to individual switch ports. FIG. 5 isa schematic diagram showing a conventional leaf-spine switch network 140having twelve spine switches 142 and twelve leaf switches 144 that areconnected in a mesh configuration using optical cabling 145, with eachleaf switch 144 having a port connected to a port of each spine switch142. Starting from the leaf switches 144, multi-fiber subunits 146 arecollected into a trunk segment 147 (typically including a jacket 147A)that spans a majority of a distance between the leaf switches 144 andthe spine switches 142. Multi-fiber subunits 148 are broken out from anend of the trunk segment 147 closest to the spine switches 142, andthereafter individual fiber segments 149 are broken out separately fromeach multi-fiber subunit 148 to connect to a port of each respectivespine switch 142. FIG. 5 shows that switch panels (e.g., including spineswitches 142) for mesh networks remain highly chaotic and unmanageable.Individual optical fibers are actually harder to trace than would besuggested by FIG. 5, since such figure illustrates just one meshconnection unit, whereas in practice a multitude of mesh connectionunits would be provided in a typical leaf-spine network.

To enhance manageability and traceability of optical fibers in meshnetwork switch panels, one solution is to insert an optical shuffle boxbetween a trunk cable and spine switch to provide a full meshcross-connector pattern. An example of such a solution is shown in FIG.6, which illustrates a leaf-spine switch network 150 that includes atrunk cable 155, an optical shuffle box 160, and jumpers 166A-166Larranged in a mesh configuration between twelve leaf switches 154 andtwelve spine switches 152, with each leaf switch 154 having a portconnected to a port of each spine switch 152. The trunk cable 155includes a trunk segment 157 within a jacket 157A, and first and secondgroups of tubes 156, 158 (also known as fanout tubes). The opticalshuffle box 160 includes a housing 161 that contains ports 162A-162L andports 164A-164L. Multiple optical fiber connections 163 are providedwithin the shuffle box 160. Use of the optical shuffle box 160 toconnect with the spine switches 152 entails use of a small number ofsimple multi-fiber jumper cables relative to the much larger number ofsingle-fiber connections that would be required in the absence of anoptical shuffle box (as shown in FIG. 5), thereby enabling awell-organized fiber layout at a switch rack supporting the spineswitches 152. Within an optical shuffle box 160, distances between theports 162A-162L and ports 164A-164L are typically substantially lessthan one meter.

Utilization of an optical shuffle box adds two multifiber connections(e.g., through each pair of serially arranged ports 162A to 164A through162L to 164L) for each link, which increases cost and also increasesoptical insertion loss. Additionally, the large number of connectionpoints per link can subject the network system to a higher probabilityof failure due to dust contamination in the connectors. Optical shuffleboxes also entail significant cost and consume valuable space insideswitch racks.

In view of the foregoing, need remains in the art for cable assembliesthat address the above-described and other limitations associated withconventional shuffle box connectivity solutions (e.g., for leaf-spinenetworking in datacenters), as well as associated fabrication methods.

SUMMARY

Aspects of the present disclosure provide fiber optic cable assemblieshaving integrated fiber shuffle regions that are suitable for meshconnectivity. An integrated fiber shuffle region is provided betweenfirst and second cable assembly sections that each include multipletubes, with each tube containing a group of optical fibers, and a jacketbeing provided over the tubes in one or both of the cable assemblysections. The first cable assembly section includes M groups of Noptical fibers and the second cable assembly section includes N groupsof M optical fibers, with the fiber shuffle region providing atransition between the respective groups of optical fibers. The opticalfibers remain in sequential order in groups at ends of the cableassembly sections, where the fibers may be ribbonized and/orconnectorized. A method for fabricating a fiber optic cable assembly isalso provided. The method comprises providing a first cable assemblysection having M groups of N optical fibers (e.g., including orderedoptical fibers O1 _(FIRST) to OX_(FIRST) as a first group and orderedoptical fibers O1 _(LAST) to OX_(LAST) as a last group). The methodfurther comprises, sequentially for each group of the M groups of Noptical fibers, inserting segments of ordered optical fibers into adifferent receiving area of a fiber sorting fixture to form multiplelinear arrays of ordered optical fibers, with a different linear arrayof ordered optical fibers within each receiving area. A first receivingarea receives optical fibers O1 _(FIRST) to O1 _(LAST) in sequentialorder to form a first linear array of optical fibers, and a lastreceiving area receives optical fibers OX_(FIRST) to OX_(LAST) insequential order to form a last linear array of optical fibers. Themethod further comprises separately fixing each linear array withadhesion elements to form rollable fixed arrays, and arranging eachrollable fixed array in a non-linear position to yield multiplerollable, non-linearly positioned fixed arrays of optical fibers. Themethod further comprises threading the plurality of rollable,non-linearly positioned fixed arrays of optical fibers through secondtubes as formative elements of a second cable assembly section thatincludes N groups of M optical fibers. The method further comprisesenclosing a transition between the M groups of N optical fibers and theN groups of M optical fibers to form an integral fiber shuffle region ofthe fiber optic cable assembly.

In one embodiment of the disclosure, a fiber optic cable assembly isprovided. The fiber optic cable assembly comprises first and secondcable assembly sections. The first cable assembly section comprises Mgroups of N optical fibers and a plurality of first tubes, wherein inthe first cable assembly section each group of the M groups of N opticalfibers is contained in a respective first tube of the plurality of firsttubes, and each group of the M groups of N optical fibers includesordered optical fibers O1 to OX as members, and further wherein M≥4 andX≥4, such that a first group of the M groups of N optical fibersincludes ordered optical fibers O1 _(FIRST) to OX_(FIRST), and a lastgroup of the M groups of N optical fibers includes ordered opticalfibers O1 _(LAST) to OX_(LAST). The second cable assembly sectioncomprises N groups of M optical fibers and a plurality of second tubes,wherein in the second cable assembly section each group of the N groupsof M optical fibers is contained in a respective second tube of theplurality of second tubes, and each group of the N groups of M opticalfibers includes one member from each group of the M groups of N opticalfibers with a like suffix 1 to X among optical fibers O1 to OX insequential order, such that a first group of the N groups of M opticalfibers includes ordered optical fibers O1 _(FIRST) to O1 _(LAST), and alast group of the N groups of M optical fibers includes ordered opticalfibers OX_(FIRST) to OX_(LAST). The fiber optic cable assembly furthercomprises a fiber shuffle region arranged between the first cableassembly section and the second cable assembly section, wherein thefiber shuffle region provides a transition between the M groups of Noptical fibers and the N groups of M optical fibers. The fiber opticcable assembly further comprises a plurality of first ribbon sections,wherein each group of the M groups of N optical fibers is contained in arespective ribbon section of the plurality of first ribbon sections, andthe first cable assembly section is arranged between the fiber shuffleregion and the plurality of first ribbon sections. The fiber optic cableassembly additionally comprises at least one of: (i) a first jacketcontaining the plurality of first tubes, or (ii) a second jacketcontaining the plurality of second tubes.

In accordance with another embodiment of the disclosure, a fiber opticcable assembly is provided. The fiber optic cable assembly comprisesfirst and second cable assembly sections. The first cable assemblysection comprises M groups of N optical fibers and a plurality of firsttubes, wherein each group of the M groups of N optical fibers iscontained in a respective first tube of the plurality of first tubes,and each group of the M groups of N optical fibers includes orderedoptical fibers O1 to OX as members, and further wherein M≥4 and X≥4,such that a first group of the M groups of N optical fibers includesordered optical fibers O1 _(FIRST) to OX_(FIRST), and a last group ofthe M groups of N optical fibers includes ordered optical fibers O1_(LAST) to OX_(LAST). The second cable assembly section comprises Ngroups of M optical fibers and a plurality of second tubes, wherein eachgroup of the N groups of M optical fibers is contained in a respectivesecond tube of the plurality of second tubes, and each group of the Ngroups of M optical fibers includes one member from each group of the Mgroups of N optical fibers with a like suffix 1 to X among opticalfibers O1 to OX in sequential order, such that a first group of the Ngroups of M optical fibers includes ordered optical fibers O1 _(FIRST)to O1 _(LAST), and a last group of the N groups of M optical fibersincludes ordered optical fibers OX_(FIRST) to OX_(LAST). The fiber opticcable assembly further comprises a fiber shuffle region arranged betweenthe first cable assembly section and the second cable assembly section,wherein the fiber shuffle region provides a transition between the Mgroups of N optical fibers and the N groups of M optical fibers. Thefiber optic cable assembly additionally comprises a first plurality ofconnectors terminating the M groups of N optical fibers of the firstcable assembly section, and a second plurality of connectors terminatingthe N groups of M optical fibers of the second cable assembly section.The fiber optic cable assembly further comprises at least one of: (i) afirst jacket containing the plurality of first tubes, or (ii) a secondjacket containing the plurality of second tubes.

In accordance with another embodiment of the disclosure, a method forfabricating a fiber optic cable assembly is provided. The methodcomprises providing M groups of N optical fibers in a first cableassembly section, with each group of the M groups of N optical fibersincluding ordered optical fibers O1 to OX as members, and wherein M≥4and X≥4, such that a first group of the M groups of N optical fibersincludes ordered optical fibers O1 _(FIRST) to OX_(FIRST), and a lastgroup of the M groups of N optical fibers includes ordered opticalfibers O1 _(LAST) to OX_(LAST). The method further comprises,sequentially for each group of the M groups of N optical fibers,inserting a segment of each ordered optical fiber into a differentreceiving area of a plurality of receiving areas of a fiber sortingfixture to form a plurality of linear arrays of optical fibers includinga different linear array of ordered optical fibers within each receivingarea, wherein a first receiving area of the plurality of receiving areasreceives optical fibers O1 _(FIRST) to O1 _(LAST) in sequential order toform a first linear array of the plurality of linear arrays of opticalfibers, and a last receiving area of the plurality of receiving areasreceives optical fibers OX_(FIRST) to OX_(LAST) in sequential order toform a last linear array of the plurality of linear arrays of opticalfibers. The method additionally comprises, for each linear array of theplurality of linear arrays of optical fibers, separately fixing at leastone segment of the linear array with at least one adhesion element toform a rollable fixed array of optical fibers, and arranging therollable fixed array of optical fibers in a non-linear position, therebyyielding a plurality of rollable, non-linearly positioned fixed arraysof optical fibers from the plurality of linear arrays of optical fibers.The method further comprises threading the plurality of rollable,non-linearly positioned fixed arrays of optical fibers through aplurality of second tubes as formative elements of a second cableassembly section including N groups of M optical fibers. The methodadditionally comprises enclosing a transition between the M groups of Noptical fibers of the first cable assembly section and the N groups of Moptical fibers of the second cable assembly section to form an integralfiber shuffle region of the fiber optic cable assembly.

Additional features and advantages will be set forth in the detaileddescription that follows, and in part will be readily apparent to thoseskilled in the technical field of optical connectivity. It is to beunderstood that the foregoing general description, the followingdetailed description, and the accompanying drawings are merely exemplaryand intended to provide an overview or framework to understand thenature and character of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding, and are incorporated in and constitute a part of thisspecification. The drawings illustrate one or more embodiment(s), andtogether with the description serve to explain principles and operationof the various embodiments. Features and attributes associated with anyof the embodiments shown or described may be applied to otherembodiments shown, described, or appreciated based on this disclosure.

FIG. 1 is a cross-sectional view of a conventional coated optical fiber.

FIG. 2 is a cross-sectional view of a conventional multi-fiber ribbonincluding twelve optical fibers.

FIG. 3 is a schematic diagram showing a conventional, non-blockingleaf-spine switch network in a full mesh configuration, with each leafswitch having a port connected to a port of each spine switch.

FIG. 4 is a schematic diagram showing a conventional super-mesh switchnetwork configuration with ninety-six leaf switches being connected toforty-eight spine switches in a full mesh network using thirty-two baseunits of mesh connectivity.

FIG. 5 is a schematic diagram showing a conventional leaf-spine switchnetwork including a trunk segment having twelve groups of twelve opticalfibers arranged in a mesh configuration between twelve leaf switches andtwelve spine switches, with each leaf switch having a port connected toa port of each spine switch.

FIG. 6 is a schematic diagram showing a conventional leaf-spine switchnetwork including a trunk cable and an optical shuffle box arranged in amesh configuration between twelve leaf switches and twelve spineswitches, with each leaf switch having a port connected to a port ofeach spine switch.

FIG. 7 is a schematic diagram showing a fiber optic cable assemblyincluding an integrated fiber shuffle region according to oneembodiment, with the fiber optic cable assembly serving as a trunkproviding a full mesh configuration between twelve leaf switches andtwelve spine switches, such that each leaf switch has a port connectedto a port of each spine switch.

FIG. 8A is a perspective view illustration of a fiber optic cableassembly including an integrated fiber shuffle region according to oneembodiment, with a first end portion having twelve groups of multiplefibers of different colors and/or markings contained in twelve firsttubes, a second end portion having twelve groups of multiple fibers eachhaving the same intra-group color contained in twelve second tubes, anda jacket containing portions of the first tubes.

FIG. 8B is a perspective view illustration of the first end portion anda reinforced jacket termination portion of the fiber optic cableassembly of FIG. 8A.

FIG. 8C is a perspective view illustration of the second end portion andintegrated fiber shuffle region of the fiber optic cable assembly ofFIG. 8A.

FIG. 9 is a schematic diagram illustrating fiber maps for transmit andreceive arrays of ribbonized optical fibers arrangeable at or beyondopposing ends of an integrated shuffle region of a fiber optic cableassembly according to one embodiment.

FIG. 10 is a perspective view illustration of a fiber sorting fixtureincluding twelve fiber holders defining fiber receiving areas in whichtwelve sorted groups of optical fibers emanating from a ribbon cablestack are arranged.

FIG. 11 is a side view illustration of an encapsulated integral fibershuffle region arranged between first and second cable assembly sectionsthat each include multiple optical fiber ribbons, according to oneembodiment.

FIG. 12 is a perspective view illustration of two stacked fiber opticcable assembly portions each including an integral fiber shuffle regionarranged between first and second cable assembly sections, with pairingbetween optical fibers having the same markings (e.g., colors).

FIG. 13 is a perspective view illustration of two fiber sorting fixtureseach including twelve fiber receiving areas in which twelve sortedgroups of optical fibers emanating from a first cable assembly section(with 288 optical fibers) are arranged.

FIG. 14 is a schematic cross-sectional view illustration of a portion ofa fiber optic cable assembly according to one embodiment, showing anintegral fiber shuffle region arranged within a containment tube thatreceives optical fibers as well as segments of tubes of first and secondcable assembly sections.

FIG. 15A is a perspective view illustration showing first and secondrollable fixed arrays of optical fibers being inserted into a first endof a tube.

FIG. 15B is a perspective view illustration showing the first and secondrollable fixed arrays of optical fibers of FIG. 15A extending through asecond end of the tube after continued insertion.

FIG. 16 is a perspective view illustration of a fiber optic cableassembly according to one embodiment, showing an integral fiber shuffleregion arranged within a containment tube that receives optical fibersas well as segments of tubes of first and second cable assemblysections.

FIG. 17A is a perspective view of an example of a multi-fiber push-on(MPO)-type fiber optic connector incorporating multiple optical fibersretained in linearly arranged bores defined in a ferrule.

FIG. 17B is an exploded view of the fiber optic connector of FIG. 17A.

FIG. 18 is a top view illustration of a fiber optic cable assemblyaccording to one embodiment, showing an integral fiber shuffle regionarranged between first and second cable assembly sections, with eachcable assembly section being terminated by a MPO-type connector.

DETAILED DESCRIPTION

Various embodiments will be further clarified by examples in thedescription below. In general, the description relates to fiber opticcable assemblies and associated fabrication methods permitting anintegrated fiber shuffle region to be provided between a first cableassembly section and a second cable assembly section, with each of thefirst and second cable assembly sections including multiple tubes eachcontaining a group of optical fibers, and with a jacket being providedover the multiple tubes in at least one of the first cable assemblysection or the second cable assembly section. The first cable assemblysection includes M groups of N optical fibers and the second cableassembly section includes N groups of M optical fibers, with the fibershuffle region providing a transition between the respective groups ofoptical fibers, and with the optical fibers remaining in sequentialorder at ends of the first and second cable assembly sections. In thefirst cable assembly section, each group of the M groups of N opticalfibers includes ordered optical fibers O1 to OX as members, wherein M≥4and X≥4, such that a first group of the M groups of N optical fibersincludes ordered optical fibers O1 _(FIRST) to OX_(FIRST), and a lastgroup of the M groups of N optical fibers includes ordered opticalfibers O1 _(LAST) to OX_(LAST). In the second cable assembly section,each group of the N groups of M optical fibers includes one member fromeach group of the M groups of N optical fibers with a like suffix 1 to Xamong optical fibers O1 to OX in sequential order, such that a firstgroup of the N groups of M optical fibers includes ordered opticalfibers O1 _(FIRST) to O1 _(LAST), and a last group of the N groups of Moptical fibers includes ordered optical fibers OX_(FIRST) to OX_(LAST).The fiber shuffle region provides a transition between the M groups of Noptical fibers of the first cable assembly section and the N groups of Moptical fibers of the second cable assembly section. Proximate to an endof one or both of the first and second cable assembly sections, multipleribbon sections and/or optical connectors may be provided.

Fiber optic cable assemblies including integrated fiber shuffle regionsaccording to various embodiments herein are suitable for making opticalcross-connections, including (but not limited to) providing meshconnectivity in leaf-spine networks.

In certain embodiments, a fiber optic cable assembly as disclosed hereinis useable as a trunk cable of any suitable length, such as at leastabout 5 meters (m), at least about 10 m, at least about 25 m, at leastabout 50 m, at least about 100 m, at least about 250 m, at least about500 m, or at least about 1000 m, wherein in certain embodiments thepreceding values may optionally be bounded by an upper limit of 2000 m.

In certain embodiments, an integrated fiber shuffle region is compact inlength and/or width, facilitating its use in optical fiber trunk cablesor the like that may be pulled within conduit, cable routing trays,cable routing troughs, or the like. Compact length dimensions arebeneficial to promote cable flexibility and permit a cable to be routedthrough turns. Compact width dimensions are beneficial to permit a cableto be routed through small openings and/or avoid being snagged on othercables during a cable pulling step. In certain embodiments, anintegrated fiber shuffle region as disclosed herein may have a maximumlength (e.g., in a direction parallel to an optical axis of opticalfibers through the cable assembly) of no greater than about 20centimeters (cm), no greater than about 10 cm, no greater than about 5cm, or no greater than about 2.5 cm. Comparatively longer lengths may benecessary when the number of optical fibers becomes large within a fibershuffle region to ensure that routing of optical fibers through thefiber shuffle region does not cause optical fibers to undergoimpermissibly small radius bends that may negatively affect opticalfiber reliability. In certain embodiments, a maximum width of anintegrated fiber shuffle region of a fiber optic cable assembly may bedefined relative to a width W_(J) of a cable jacket (e.g., a jacket thatsurrounds subunit tubes of the cable assembly), such as a width of nogreater than about 1.6×W_(J), no greater than about 1.5×W_(J), nogreater than about 1.25×W_(J), no greater than about 1.15×W_(J), nogreater than about 1.1×W_(J), no greater than about 1.05×W_(J), or nogreater than about 1×W_(J).

In certain embodiments, an integrated fiber shuffle region of a fiberoptic cable assembly as disclosed herein includes a tubular bodydefining a cavity that contains a transition between M groups of Noptical fibers of a first cable assembly section and N groups of Moptical fibers of a second cable assembly section. Such a tubular body,which may also be referred to as a furcation, may include any desirablecross-sectional shape, such as round, oval, rectangular, polygonal, orthe like. In certain embodiments, one or both ends of the tubular bodymay be sealed with a plug and/or a sealant. In certain embodiments, anencapsulant material is provided within the cavity and arranged incontact with exterior portions of the M groups of N optical fibers andthe N groups of M optical fibers. In certain embodiments, theencapsulant material is configured to remain solid over an entireanticipated operating range of a fiber optic cable assembly (e.g., from−10° C. to 100° C. or any other suitable temperature range). Examples ofsuitable encapsulant materials include epoxies, thermoplastic materials,and curable adhesive materials (e.g., of photocurable, thermallycurable, and/or chemically curable varieties). In certain embodiments,an encapsulant material is supplied in liquid form to the cavity oftubular body containing an integral fiber shuffle region, and theencapsulant material is cured or otherwise solidified to form a solidencapsulant that contacts exterior portions of the M groups of N opticalfibers and the N groups of M optical fibers within the cavity.

In certain embodiments, an integral fiber shuffle region may include asolid material encapsulating exterior portions of the M groups of Noptical fibers and the N groups of M optical fibers without beingcontained in a tubular body. In certain embodiments, the solid materialmay be formed by molding (e.g., low pressure molding) around a fibertransition region in contact with exterior portions of the M groups of Noptical fibers and the N groups of M optical fibers.

In certain embodiments, a fiber optic cable assembly as disclosed hereinincludes M groups of N optical fibers in a first cable assembly section,and N groups of M optical fibers in a second cable assembly section,wherein various values of M and N may be used. In certain embodiments, Mequals N. In certain embodiments, M does not equal N. In certainembodiments, M and N are both at least four. In certain embodiments, atleast one of M or N is at least eight, at least twelve, at leastsixteen, or at least twenty-four. In certain embodiments, M=1.5N, M=2N,M=3N, N=1.5M, N=2M, or N=3M. In certain embodiments, each tube arrangedin a cable assembly section contains multiple (e.g., 2, 4, 6, 16, ormore) optical fibers therein.

In certain embodiments, the first and/or second cable assembly sectionsmay include multiple tubes each containing groups of optical fibers,wherein portions of such tubes extend into a fiber shuffle region. Incertain embodiments, the first and/or second cable assembly sections ofa fiber optic cable assembly may include strength members (e.g., offibrous, string-like, or yarn-like material, such as aramid yarn) thatextend in a direction generally parallel with an optical axis of opticalfibers within the respective cable assembly sections, wherein portionsof the strength members extend into a fiber shuffle region. In certainembodiments, encapsulant material of such a fiber shuffle region may bearranged in contact with tube end segments, jacket end segments, and/orstrength members of one or both of the first and second cable assemblysections that extend into the fiber shuffle region. Encapsulation ofstrength members within the fiber shuffle region may enhance the tensilestrength of a resulting fiber optic cable assembly, which may bebeneficial when pulling a trunk cable incorporating an integrated fibershuffle region over a long distance and/or through a tortuous path asmay be experienced by a cable within conduits, cable trays, or cabletroughs. Encapsulation of tube end segments and/or jacket end segmentswithin a fiber shuffle region may beneficially serve to securerespective end segments and prevent their separation from the fibershuffle region, thereby enhancing environmental protection of opticalfibers contained therein, and potentially increasing tensile strength ofthe cable assembly.

Fiber optic cable assemblies according to certain embodiments disclosedherein may include groups of optical fibers arranged as tight bufferedoptical fibers, loose tube optical fibers, ribbonized optical fibers(including flat ribbons or rollable ribbons), or combinations thereof(e.g., at opposing ends of a fiber optic cable assembly). In certainembodiments, tubes extending from a jacketed trunk segment or from anintegral fiber shuffle region may include optical fibers according toany one or more of the preceding formats. In certain embodiments,optical fiber groups may be sequentially ribbonized proximate to endsthereof and connectorized (e.g., with single-fiber or multi-fiberconnectors).

In certain embodiments, a first cable assembly section includes aplurality of first tubes, and in the first cable assembly section, eachgroup of the M groups of N optical fibers is loosely contained in arespective first tube of the plurality of first tubes. As used in thisdisclosure, “loosely contained” or “loosely arranged” refers to groupsof optical fibers being devoid of a matrix material encapsulating alloptical fibers of a particular group over at least some common length ofthe optical fibers. In certain embodiments, “loosely contained” or“loosely arranged” groups of optical fibers may include groups ofoptical fibers that are intermittently bound (i.e., not fullyencapsulated). In certain embodiments, a second cable assembly sectionincludes a plurality of second tubes, and in the second cable assemblysection, each group of the N groups of M optical fibers is looselycontained in a respective second tube of the plurality of second tubes.Such tubes may include any desirable cross-sectional shape, such asround, oval, rectangular (e.g., square), polygonal, or the like.

Depending on tube dimensions, it may be difficult to thread ribbonizedoptical fibers through a plurality of first tubes or a plurality ofsecond tubes during fabrication of a fiber optic cable assembly asdisclosed herein. To address this issue, in certain embodiments, (i)each tube of the plurality of first tubes in a first cable assemblysection is rectangular or square in cross-section, and each group of theM groups of N optical fibers is ribbonized within a respective firsttube of the plurality of first tubes; and/or (ii) each tube of theplurality of second tubes in a second cable assembly section isrectangular or square in cross-section, and each group of the N groupsof M optical fibers is ribbonized within a respective second tube of theplurality of second tubes.

In certain embodiments, groups of non-ribbonized optical fibers arearranged in ordered linear arrays along at least one or more lengthwisesegments of such groups within respective tubes of first and/or secondcable assembly sections. According to such embodiments, the positioningof optical fibers within each linear array may be maintained using atleast one adhesion element that may stick to the arrayed optical fibersto form a joined or “fixed” array of optical fibers. Such fixed arraysare preferably rollable in character to form rollable fixed arrays,wherein a rollable fixed array may include arrayed optical fibers in alinear one-dimensional conformation when in an unrolled position, andmay include arrayed optical fibers in a non-linear conformation (e.g.,folded, encircled, or spiral-rolled) when in a rolled position. Incertain embodiments, an adhesion element may include a single-sidedself-adhesive material including a carrier (e.g., of one or morepolymers or metals) and an adhesive layer bound thereto. Multipleadhesion elements may be used at spaced-apart locations to formintermittently-fixed array segments. Use of one or more adhesionelements to maintain positioning of optical fibers in an array permits arollable fixed array of optical fibers to be inserted through a tube(e.g., in a rolled position) during a cable assembly fabrication stepand then manipulated into an unrolled position following such insertionwithout any need for re-sorting optical fibers (e.g., to permitconnectorization). In certain embodiments, an adhesion element includesa plastically deformable adhesion element, such as a metal foil (e.g.,copper foil) tape. Use of a plastically deformable adhesion elementpermits at least a segment of a rollable fixed optical fiber array to bearranged in a non-linear (e.g., folded, encircled, or spiral-rolled)position before threading the rollable fixed array through a tube,thereby reducing the maximum width of the rollable fixed optical fiberarray (and reducing the internal width requirement for the bore of thetube) to ease passage through the tube. After the rollable fixed arraysegment arranged in a non-linear position is threaded through a tube,the rollable fixed array segment may be unfolded or unrolled to returnthe rollable fixed array segment to a linear shape. Thereafter, an endportion of the optical fiber array may be ribbonized and/orconnectorized.

In certain embodiments, within each group of optical fibers in the firstcable assembly section, each optical fiber comprises a colored outercoating or surface of a same color scheme, and within each group ofoptical fibers in the second cable assembly section, each optical fibercomprises a colored outer coating or surface of a same color scheme.Each of the first and second cable assembly sections may include fibergroups contained within multiple tubes. In such an embodiment, anintegrated fiber shuffle region arranged between the first and secondcable assembly sections serves to distribute one fiber from each firsttube into a different single tube of the multiple second tubes. If eachfirst tube contains optical fibers of different colors or markingschemes, then each second tube contains optical fibers of a single coloror marking scheme, with the color or marking scheme of fibers indifferent second tubes differing from one another. In certainembodiments, each tube in the first cable assembly section of a fiberoptic cable assembly has a different marking scheme and/or color scheme,and each tube in the second cable assembly section has a differentmarking scheme and/or color scheme.

In certain embodiments, each tube of first and/or second cable assemblysections may be preterminated with a single multi-fiber connector,multiple multi-fiber connectors, multiple single-fiber connectors, orharnesses of any suitable configuration.

It is to be emphasized that integrated fiber shuffle regions accordingto some embodiments are devoid of any splices and interconnects betweensegments of any optical fibers (e.g., between segments of the M groupsof N optical fibers and the N groups of M optical fibers). Suchembodiments are enabled by the processing techniques according to thisdisclosure. In this regard, fiber optic cable assemblies incorporatingthese integrated fiber shuffle regions avoid the need for internalconnections that would increase optical insertion loss and eliminate anypossibility of dust contamination.

Having introduced the preceding concepts, additional features ofembodiments disclosed herein will be described with reference to theaccompanying figures.

FIG. 7 is a schematic diagram showing a fiber optic cable assembly 180including an integrated fiber shuffle region 186 according to oneembodiment, with the fiber optic cable assembly 180 serving as a trunkproviding a full mesh configuration between twelve leaf switches 174 andtwelve spine switches 172 as part of a leaf-spine network 170. In theleaf-spine network 170, the fiber optic cable assembly 180 permits aport of each leaf switch 174 to be connected to a port of each spineswitch 172. The integrated fiber shuffle region 186 is provided betweena first cable assembly section 181 and a second cable assembly section182. The first cable assembly section 181 includes multiple groups ofoptical fibers separately arranged in multiple first tubes 183 that arefurther contained within a jacket 185 along the length of a trunksegment 184. A transition structure 188 may be arranged at one end ofthe trunk segment 184, with segments of individual first tubes 183external to the trunk segment 184 being routed to the leaf switches 174.The trunk segment 184 may have any suitable length for the end use, suchas in one or more length ranges specified previously herein. Theintegrated fiber shuffle region 186 is arranged at an opposing end ofthe trunk segment 184, with the integrated fiber shuffle region 186serving to distribute one fiber from each first tube 183 into adifferent single tube 189 of the second cable assembly section 182. Theintegrated fiber shuffle region 186 includes a body 187, which mayinclude solid material encapsulating exterior portions of the opticalfibers in the integrated fiber shuffle region 186.

FIG. 8A is a perspective view illustration of a fiber optic cableassembly 190 according to one embodiment, including an integrated fibershuffle region 196 arranged between a first cable assembly section 191and a second cable assembly section 192. The fiber optic cable assembly190 has a first end portion (bottom of FIG. 8A) with twelve groups ofmultiple optical fibers 203 that each include optical fibers havingdifferent external colors and/or markings. The twelve groups of multipleoptical fibers 203 respectively extend from twelve first tubes 201. Thetwelve first tubes 201 extend from a reinforced transition segment 198arranged at one end of a trunk segment having a jacket 195 that containsthe first tubes 201 therein. The fiber optic cable assembly 190 alsoincludes a second end portion (top of FIG. 8A) with twelve groups ofmultiple optical fibers 204 having different external colors and/ormarkings between respective groups, but the same external color and/ormarking within each individual group. The twelve groups of multipleoptical fibers 204 respectively extend from twelve second tubes 202. Thetwelve second tubes 202 extend from the integrated fiber shuffle region196, which includes a body 197 having a solid material that encapsulatesexternal surfaces of optical fibers from the first cable assemblysection 191 and the second cable assembly section 192. Although notshown in FIG. 8A, it is to be appreciated that respective groups ofoptical fibers 203, 204 proximate to ends of the fiber optic cableassembly 190 may be ribbonized and/or connectorized in certainembodiments. Thus, the groups of optical fibers 203 may each beribbonized to form a plurality of first ribbon sections, and/or thegroups of optical fibers 204 may each be ribbonized to form secondribbon sections.

FIG. 8B is a magnified perspective view of the first end portion of thefiber optic cable assembly 190 of FIG. 8A. At one end of the trunksegment bounded by the jacket 195, the reinforced transition segment 198defines a cavity through which twelve first tubes 201A-201L extend. Eachfirst tube 201A-201L contains a corresponding group of multiple opticalfibers 203A-203L (collectively, optical fibers 203). The optical fibers203 have different external colors and/or markings within each group203A-203L, but each group 203A-203L has the same combination ofdifferently colored and/or marked optical fibers 203. In certainembodiments, each first tube 201A-201L may be provided with a differentcolor scheme and/or marking scheme. In certain embodiments, each groupof multiple optical fibers 203A-203L includes twenty-four opticalfibers, consisting of twelve transmit optical fibers and twelve receiveoptical fibers, accommodating twelve communication links.

FIG. 8C is a magnified perspective view of the second end portion of thefiber optic cable assembly 190 of FIG. 8A, including the second cableassembly section 192 and the integrated fiber shuffle region 196, whichis arranged at an end of the trunk segment bounded by the jacket 195.The integrated fiber shuffle region 196 includes a body 197 defining acavity 196′ through which twelve second tubes 202A-202L extend. Eachsecond tube 202A-202L contains a corresponding group of multiple opticalfibers 204A-204L (collectively, optical fibers 204). The optical fibers204 have different external colors and/or markings between respectivegroups 204A-204L, but the same external color and/or marking within eachindividual group 204A-204L. In certain embodiments, each second tube202A-202L may be provided with a different color scheme and/or markingscheme. In certain embodiments, each group of multiple optical fibers204A-204L includes twenty-four optical fibers, consisting of twelvetransmit optical fibers and twelve receive optical fibers, accommodatingtwelve communication links.

It is to be appreciated that optical fibers 203 in each group of thefirst group of multiple optical fibers 203A-203L and optical fibers 204in each group of the second group of multiple optical fibers 204A-204Lmay be provided and fixed in a specific sequence or order, therebypermitting the respective fiber groups to be ribbonized and/orconnectorized without any need for resorting or re-ordering opticalfibers. Such order may be maintained by any suitable member(s)connecting or joining the groups of optical fibers 203A-203L, 204A-204Lwithin the corresponding tubes 201A-201L, 202A-202L, or as discussedbelow, at least connecting the groups of optical fibers 203A-203L,204A-204L as they are being inserted through the corresponding tubes201A-201L, 202A-202L. Examples of suitable members for connecting groupsof optical fibers include adhesion elements (e.g., copper foil tape)placed at intermittent locations and inter-fiber binders (not shown)placed intermittently between the optical fibers (e.g., as may be usedto yield rollable ribbons or the like).

Although the embodiment of FIGS. 8A-8C illustrate the use of fibergroups that may be loosely arranged within tubes, certain embodimentsprovided herein may utilize ribbonized optical fibers at or downstreamof opposing ends of a fiber shuffle region.

FIG. 9 provides fiber maps for dedicated transmit arrays 210T_(A),210T_(B) and receive arrays 210R_(A), 210R_(B) of ribbonized opticalfibers arrangeable at (or beyond) opposing first and second ends of atleast one integrated fiber shuffle region (not shown) of a fiber opticcable assembly according to one embodiment. Although the transmit arrays210T_(A), 210T_(B) and receive arrays 210R_(A), 210R_(B) compriseribbonized optical fibers, it is to be understood that in a fibershuffle region, optical fibers therein are not ribbonized. Starting atthe upper left of FIG. 9, the transmit array 210T_(A) includes twelveoptical fiber ribbons T1 _(A)-T12 _(A) that each contain a group oftwelve optical fibers (ranging from O1 _(FIRST)-O12 _(FIRST) for thefirst ribbon T1 _(A), to O1 _(LAST)-O12 _(LAST) for the last ribbon T12_(A)) joined by a matrix material 212A. As shown, each optical fiberribbon T1 _(A)-T12 _(A) of the transmit array 210T_(A) includes opticalfibers of different external colors and/or markings within therespective ribbon T1 _(A)-T12 _(A), but each optical fiber ribbon T1_(A)-T12 _(A) has the same combination of differently colored and/ormarked optical fibers. Shifting to the lower left of FIG. 9, the receivearray 210R_(A) includes twelve optical fiber ribbons R1 _(A)-R12 _(A)that each contain a group of twelve optical fibers (ranging from O1_(FIRST)-O12 _(FIRST) for the first ribbon R1 _(A), to O1 _(LAST)-O12_(LAST) for the last ribbon R12 _(A)) joined by a matrix material 214A.As shown, each optical fiber ribbon R1 _(A)-R12 _(A) of the receivearray 210R_(A) includes optical fibers of different external colorsand/or markings within the respective ribbon R1 _(A)-R12 _(A), but eachoptical fiber ribbon R1 _(A)-R12 _(A) has the same combination ofdifferently colored and/or marked optical fibers. It is to be understoodthat at least one fiber shuffle region (e.g., a first fiber shuffleregion, not shown) is arrangeable between the transmit arrays 210T_(A),210T_(B), and at least one fiber shuffle region (e.g., a second fibershuffle region, not shown) is arrangeable between the receive arrays210R_(A), 210R_(B).

Turning to the upper right of FIG. 9, each optical fiber ribbon T1_(B)-T12 _(B) of the transmit array 210T_(B) includes twelve opticalfibers (ranging from O1 _(FIRST)-O1 _(LAST) for the first ribbon T1_(B), to O12 _(FIRST)-O12 _(LAST) for the last ribbon T12 _(B)) joinedby a matrix material 212B. As shown, each optical fiber ribbon T1_(B)-T12 _(B) of the transmit array 210T_(B) includes the same externalcolor and/or marking for optical fibers within each individual ribbon T1_(B)-T12 _(B), but different external colors and/or markings betweenrespective ribbons T1 _(B)-T12 _(B). Shifting to the lower right of FIG.9, each optical fiber ribbon R1 _(B)-R12 _(B) of the receive array210R_(B) includes twelve optical fibers (ranging from O1 _(FIRST)-O1_(LAST) for the first ribbon R1 _(B), to O12 _(FIRST)-O12 _(LAST) forthe last ribbon R12 _(B)) joined by a matrix material 214B. As shown,each optical fiber ribbon R1 _(B)-R12 _(B) of the receive array 210R_(B)includes the same external color and/or marking for optical fiberswithin each individual ribbon R1 _(B)-R12 _(B), but different externalcolors and/or markings between respective ribbons R1 _(B)-R12 _(B).

Although FIG. 9 depicts transmit ribbons T1 _(A)-T12 _(A), T1 _(B)-T12_(B) grouped in transmit arrays 210T_(A), 210T_(B) arranged separatelyfrom receive ribbons R1 _(A)-R12 _(A), R1 _(B)-R12 _(B) grouped inreceive arrays 210R_(A), 210R_(B), as may be appropriate proximate to afiber shuffle region, it is to be appreciated that proximate to ends ofa fiber optic cable assembly, each transmit ribbon may be paired with acorresponding receive ribbon for connectorization in a MPO-type orsimilar multifiber connector (e.g., including an upper row of transmitfibers and a lower row of receive fibers). For example, distal from afiber shuffle region (not shown) and proximate to a first end of a fiberoptic cable assembly, a first connector may receive an upper row ofoptical fibers from transmit ribbon T1 _(A) and a lower row of opticalfibers from corresponding receive ribbon R1 _(A), whereas a twelfthconnector may receive an upper row of optical fibers from transmitribbon T12 _(A) and a lower row of optical fibers from correspondingreceive ribbon R12 _(A). Similarly, distal from a fiber shuffle region(not shown) and proximate to a second end of a fiber optic cableassembly, a first connector may receive an upper row of optical fibersfrom transmit ribbon T1 _(B) and a lower row of optical fibers fromcorresponding receive ribbon R1 _(B), whereas a twelfth connector mayreceive an upper row of optical fibers from transmit ribbon T12 _(B) anda lower row of optical fibers from corresponding receive ribbon R12_(B).

FIG. 10 is a perspective view illustration of a fiber sorting fixture225 including twelve fiber holders 224A-224L each including a fiberreceiving area 226A-226L, with the fiber sorting fixture 225 receivingtwelve sorted groups of optical fibers 228A-228L emanating from a ribboncable stack 221, as part of an intermediate product 220 for fabricatinga fiber optic cable assembly according to one embodiment. In certainembodiments, individual optical fibers may be separated from the ribboncable stack 221, with optical fibers of the same color scheme or markingscheme being sequentially inserted into the same fiber receiving areaamong the multiple fiber receiving areas 226A-226L, and with opticalfibers emanating from the same ribbon being inserted at correspondingpositions (e.g., first, second, or third, etc.) in respective fiberreceiving areas 226A-226L. In certain embodiments, each fiber receivingarea 226A-226L may include a slot having a width configured to receive asingle fiber, and a depth configured to receive multiple fibers arrangedin a one-dimensional (e.g., vertical) array, whereby upon sequentialinsertion of optical fibers into the fiber receiving area 226A-226L, theoptical fibers will be maintained in the same order in which they wereinserted. A fiber transition region 222 is provided between the ribboncable stack 221 and the fiber sorting fixture 225. When all fibersemanating from the ribbon cable stack 221 have been sorted andpositioned in respective fiber receiving areas 226A-226L, adhesionelements (e.g., metal foil tape or the like, not shown) may beseparately applied around each sorted group of optical fibers 228A-228L(e.g., proximate to the fiber holders 224A-224L) to separately join orfix the sorted groups of optical fibers 228A-228L in order to permitpositioning between optical fibers within the respective groups ofoptical fibers 228A-228L to be maintained after the groups of opticalfibers 228A-228L are removed from the fiber sorting fixture 225.Following removal of the groups of optical fibers 228A-228L from thefiber sorting fixture 225, the fiber transition region 222 (or a segmentthereof) may be contained within a tubular body and/or a solidencapsulant material to provide a fiber shuffle region of a fiber opticcable assembly.

FIG. 11 is a side view illustration of an encapsulated integral fibershuffle region 236 arranged between first and second cable assemblysections 231, 232. The first cable assembly section 231 includesmultiple optical fiber ribbons 233, and the second cable assemblysection 232 includes multiple optical fiber ribbons 234. The fibershuffle region 236 includes a body 237 having a solid material thatencapsulates external surfaces of optical fibers from the first cableassembly section 231 and the second cable assembly section 232. Asshown, a width of the fiber shuffle region 236 may be substantiallyequal to a width of each of the first and second cable assembly sections231, 232, and the fiber shuffle region 236 may have a length of nogreater than about 5 cm, or no greater than about 2.5 cm, according toone embodiment. During fabrication, terminal portions of optical fiberribbons 233 of the first cable assembly section 231 may bede-ribbonized, then sorted by different fiber colors with a transitionregion being encapsulated in the body 237 to form the fiber shuffleregion 236, and fiber segments downstream of the fiber shuffle region236 may be re-ribbonized to form the optical fiber ribbons 234 of thesecond cable assembly section 232. The technique shown and describedwith reference to FIG. 10 may be used, for example.

FIG. 12 is a perspective view illustration of two stacked fiber opticcable assembly portions each including an integral fiber shuffle region246-1, 246-2 arranged between a respective first cable assembly section241-1, 241-2 and a second cable assembly section 242-1, 242-2. Eachfirst cable assembly section 241-1, 241-2 includes a respectivemulti-fiber ribbon 243-1, 243-2. The second cable assembly sections242-1, 242-2 each include multiple optical fibers 244-1A to 244-1L,244-2A to 244-2L In the second cable assembly sections 242-1, 242-2,optical fibers 244-1A, 244-2A to 244-1L, 244-2L having correspondingmarkings (e.g., colors) are paired with one another, to prepare eachdifferent optical fiber pair for insertion into a respective tube (notshown) to continue fabrication of a fiber optic cable assembly (e.g.,ribbonization and/or connectorization of ends of the paired opticalfibers 244-1A, 244-2A to 244-1L, 244-2L).

FIG. 13 is a perspective view illustration of two fiber sorting fixtures265-1, 265-2 each including twelve respective fiber holders 264-1A to264-1L and 264-2A to 264-2L, with each fiber holder 264-1A to 264-1L and264-2A to 264-2L including a fiber receiving area 266-1A to 266-1L and266-2A to 266-2L. In certain embodiments, each fiber receiving area266-1A to 266-1L and 266-2A to 266-2L may include a slot having a widthconfigured to receive a single fiber, and a depth configured to receivemultiple fibers arranged in a one-dimensional (e.g., vertical) array.The first fiber sorting fixture 265-1 receives twelve sorted groups oftransmit optical fibers 268-1A to 268-1L (e.g., with twelve opticalfibers per group) emanating from loose tubes 253 contained in a jacketof a first cable assembly section 251, and the second sorting fixture265-2 receives twelve sorted groups of receive optical fibers 268-2A to268-2L (e.g., with twelve optical fibers per group) emanating from theloose tubes 253 of the first cable assembly section 251, all as part ofan intermediate product 250 for fabricating a fiber optic cable assemblyaccording to one embodiment. For the first fiber sorting fixture 265-1,individual transmit optical fibers may be separated from the loose tubes253 (emanating from a jacket 251A), with optical fibers of the samecolor scheme or marking scheme being sequentially inserted into the samefiber receiving area among the multiple fiber receiving areas 266-1A to266-1L, and with optical fibers emanating from the same loose tube 253being inserted at corresponding positions (e.g., first, second, orthird, etc.) in respective fiber receiving areas 266-1A to 266-1L.Similarly, for the second fiber sorting fixture 265-2, individualtransmit optical fibers may be separated from the loose tubes 253, withoptical fibers of the same color scheme or marking scheme beingsequentially inserted into the same fiber receiving area among themultiple fiber receiving areas 266-2A to 266-2L, and with optical fibersemanating from the same loose tube 253 being inserted at correspondingpositions (e.g., first, second, or third, etc.) in respective fiberreceiving areas 266-2A to 266-2L. Upon sequential insertion of opticalfibers into the fiber receiving areas 266-1A to 266-1L and 266-2A to266-2L, optical fibers will be maintained in the same order in whichthey were inserted. Fiber transition regions 260-1, 260-2 are providedbetween the first cable assembly section 251 and the fiber sortingfixtures 265-1, 265-2. When all fibers emanating from the first cableassembly section 251 have been sorted and positioned in respective fiberreceiving areas 266-1A to 266-1L and 266-2A to 266-2L, adhesion elements(e.g., metal foil tape or the like, not shown) may be separately appliedaround each sorted group of optical fibers 268-1A to 268-1L, 268-2A to268-2L (e.g., proximate to the fiber holders 264-1A to 264-1L, 264-2A to264-2L) to separately fix the sorted groups of optical fibers 268-1A to268-1L, 268-2A to 268-2L in order to maintain positioning betweenoptical fibers within the respective groups of optical fibers 268-1A to268-1L, 268-2A to 268-2L after their removal from the fiber sortingfixtures 265-1, 265-2. Following removal of the groups of optical fibers268-1A to 268-1L, 268-2A to 268-2L from the fiber sorting fixtures265-1, 265-2, both fiber transition regions 260-1, 260-2 (or shortenedsegments thereof) may be contained within a tubular body and/or a solidencapsulant material to provide a fiber shuffle region of a fiber opticcable assembly (e.g., the fiber shuffle region 186 of the fiber opticcable assembly 180 of FIG. 7). In certain embodiments, one sorted androllable fixed group of transmit optical fibers (e.g., optical fibergroup 268-1A) may be paired with one corresponding sorted and rollablefixed group of receive optical fibers (e.g., optical fiber group268-2A), optionally each arranged in a non-linear position, and threadedthrough a single tube (not shown), and the process may be repeated foreach pair of optical fiber groups until multiple tubes each containing adifferent rollable fixed transmit fiber group and receive fiber group isprovided. Thereafter, one multi-fiber connector per tube may be used toterminate each paired optical fiber group to include correspondingtransmit and receive fibers as part of a fiber optic cable assembly.

FIG. 14 is a schematic cross-sectional view illustration of a portion ofa fiber optic cable assembly 270 according to one embodiment, showing anintegral fiber shuffle region 276 arranged within a tubular body 277(which may also be referred to as a furcation) defining an internalcavity 278 that protects optical fiber cross-connections between firstand second cable assembly sections 271, 272. In certain embodiments, thetubular body 277 comprises a heat shrink material (e.g., heat shrinktubing). The first cable assembly section 271 includes multiple firsttubes 281A-281X as well as strength members 287 contained within a firstjacket 283, with each first tube 281A-281X containing multiple opticalfibers 280. The second cable assembly section 272 includes multiplesecond tubes 282A-282X as well as strength members 286 contained withina second jacket 284, with each second tube 282A-282X containing multipleoptical fibers 280. From the first cable assembly section 271, theinternal cavity 278 of the tubular body 277 receives optical fibers 280,end segments of the first tubes 281A-281X, end portions of strengthmembers 287, and an end portion of the jacket 283. A plug member 275 isprovided at one end of the tubular body 277. From the second cableassembly section 272, the internal cavity 278 of the tubular body 277receives optical fibers 280, as well as end segments of the second tubes282A-282X and end portions of strength members 286 that both extendthrough the plug member 275. Within the cavity 278 of the tubular body277, an encapsulant material 279 is provided in contact with the opticalfibers 280, the first and second tubes 281A-281X, 282A-282X, thestrength members 286, 287, the first jacket 283, and the plug member275. Presence of the encapsulant material 279 in the cavity 278 providesmechanical support for the optical fibers 280, while contact betweenencapsulant material 279 and the strength members 286, 287 (as well ascontact between the encapsulant material 279 and the first and secondtubes 281A-281X, 282A-282X and the jacket 283) may enhance tensilestrength of the fiber optic cable assembly 270 and therefore provideenhanced reliability.

FIGS. 15A and 15B are perspective view illustrations showing thepositioning of first and second rollable fixed arrays of optical fibers291A, 291B relative to a tube 292 defining a cavity 293 therein, whereineach rollable fixed array of optical fibers 291A, 291B includes anadhesion element 295A, 295B arranged to maintain positioning of opticalfibers and thereby define rollable fixed array segments. In FIG. 15A,the first and second rollable fixed arrays of optical fibers 291A, 291Bare arranged in non-linear positions and shown as being inserted into afirst end 292′ of the tube 292. The adhesion elements 295A, 295B arestaggered with respect to axial position to ease insertion of therollable fixed arrays of optical fibers 291A, 291B through the tube 292.In FIG. 15B, the first and second rollable fixed arrays 291A, 291B ofoptical fibers are shown as extending through a second end 292″ of thetube 292 following continued insertion. In certain embodiments, thefirst rollable fixed array of optical fibers 291A consists of transmitfibers and the second rollable fixed array of optical fibers 291Bconsists of receive fibers. Following insertion of the first and secondrollable, non-linearly positioned fixed arrays of optical fibers 291A,291B through the tube 292, the first and second rollable fixed arrays ofoptical fibers 291A, 291B may be returned to linear positions, andribbonized and/or connectorized together.

FIG. 16 is a perspective view illustration of a fiber optic cableassembly 300 according to one embodiment, showing an integral fibershuffle region 306 having a tubular body 307 and arranged between firstand second cable assembly sections. 301, 302. The first cable assembly301 includes a jacket 313 containing multiple first tubes 311A-311L thateach contain a group of optical fibers. When the first tubes 311A-311Lemanate from the jacket 313, they may be referred to as fanout tubes.The second cable assembly 302 includes multiple second tubes 312A-312L(also known as fanout tubes) that each contain a group of opticalfibers. In the integral fiber shuffle region 306, the tubular body 307receives a portion of the jacket 313 at one end, and receives a plugmember 305 at an opposing end. The tubular body 307 further receives endsegments of the first tubes 311A-311L and end segments of the secondtubes 312A-312L, as well as optical fibers 308 establishing opticalcross-connection between the respective first tubes 311A-311L and secondtubes 312A-312L. While FIG. 16 shows optical fibers 308 as extendingbeyond the first tubes 311A-311L and the second tubes 312A-312L in thefirst cable assembly section 301 and the second cable assembly section302, respectively, it is to be appreciated that optical fibers proximateto ends of the first tubes 311A-311L and the second tubes 312A-312L maybe ribbonized and/or connectorized. Such ribbonization and/orconnectorization at one or more terminal ends of the fiber optic cableassembly 300 may be performed in a factory or in a field setting

FIGS. 17A and 17B show a multi-fiber push-on (MPO)-type connector 375installed on a fiber optic cable 376 to form a fiber optic cableassembly 377. The MPO-type connector 375 includes a ferrule 378, ahousing 379 received over the ferrule 378, a slider or slide lock 380received over the housing 379, and a boot 381 received over the fiberoptic cable 376. The ferrule 378 is spring-biased within the housing 379so that a front portion 382 of the ferrule 378 extends beyond a frontend 383 of the housing 379. Multiple optical fibers (not shown) carriedby the fiber optic cable 376 extend through bores 384 (also known asmicro-holes) defined in the ferrule 378 before terminating at or near afront end face 385 of the ferrule 378. The optical fibers are securedwithin the ferrule 378 as described above, such as by using an adhesivematerial (e.g., epoxy). The optical fibers can be presented for opticalcoupling with optical fibers of a mating component (e.g., another fiberoptic connector; not shown) when the housing 379 is inserted into anadapter, receptacle, or the like.

As shown in FIG. 17B, the MPO-type connector 375 also includes a ferruleboot 386, guide pin assembly 387, spring 388, crimp body 389, and crimpring 390. Optical fibers extend through an aperture defined through theferrule boot 386. The guide pin assembly 387 includes a pair of guidepins 392 extending from a pin keeper 393. When the MPO-type connector375 is assembled, the pin keeper 393 is positioned against a backsurface of the ferrule 378, and the guide pins 392 extend through pinholes 394 (shown in FIG. 17A) provided in the ferrule 378 so as toproject beyond the front end face 385 of the ferrule 378. Both theferrule 378 and guide pin assembly 387 are biased to a forward positionrelative to the housing 379 by the spring 388, which is positionedbetween the pin keeper 393 and a portion of the crimp body 389. Thecrimp body 389 includes latching arms 395 that engage recesses 396 inthe housing 379. A rear portion 391 of the ferrule 378 defines a flangethat interacts with a shoulder or stop formed within the housing 379 forretention of the rear portion 391 of the ferrule 378 in the housing 379.In a manner not shown in the figures, strength members (e.g., aramidyarn) from the fiber optic cable 376 may be positioned over an endportion 397 of the crimp body 389 that projects rearwardly from thehousing 379, and the strength members are secured to the end portion 397by deformation of the crimp ring 390. The boot 381 covers this region,as shown in FIG. 17A, and provides strain relief for optical fibersemanating from the fiber optic cable 376 by limiting the extent to whichthe MPO-type connector 375 can bend relative to the fiber optic cable376.

FIG. 18 is a top view illustration of a fiber optic cable assembly 400according to one embodiment, including an integral fiber shuffle region406 arranged between first and second cable assembly sections 401, 402.The first cable assembly section 401 includes a jacketed trunk segment410 that contains multiple first tubes 411A-411L each containing a groupof optical fibers therein. A transition structure 409 is arranged at oneend of the trunk segment 410, where segments of individual first tubes411A-411L (also known as fanout tubes) emerge from the trunk segment410, with terminal portions of optical fibers from the first tubes411A-411L being terminated at connectors 415A-415L. Terminal portions ofthe optical fibers from the first tubes 411A-411L may also be ribbonizedto form ribbon sections 413A-413L (arranged within connectors 415A-415L)prior to connectorization. The first cable assembly section 401 includesa jacketed trunk segment 410 that contains multiple first tubes411A-411L each containing a group of optical fibers therein. Atransition structure 409 is arranged at one end of the trunk segment410, where segments of individual first tubes 411A-411L emerge from thetrunk segment 410, with terminal portions of optical fibers from thefirst tubes 411A-411L being terminated at connectors 415A-415L. Terminalportions of the optical fibers from the first tubes 411A-411L may alsobe ribbonized to form ribbon sections 413A-413L (arranged withinconnectors 415A-415L) prior to connectorization. As illustrated, theconnectors 415A-415L are MPO-type connectors permitting termination ofmultiple optical fibers (e.g., 4, 8, 12, 16, 24, 32, 48, etc.) in one ormore rows. The second cable assembly section 402 includes multiplesecond tubes 412A-412L each containing a group of optical fiberstherein. A transition structure 409 is arranged at one end of a jacketto provide reinforcement where segments of individual second tubes412A-412L emerge, with terminal portions of optical fibers from thesecond tubes 412A-412L (also known as fanout tubes) being terminated atconnectors 416A-416L. Terminal portions of the optical fibers from thesecond tubes 412A-412L may also be ribbonized to form ribbon sections414A-414L (arranged within connectors 416A-416L) prior toconnectorization. As shown, the connectors 415A-415L, 416A-416L areMPO-type connectors permitting termination of multiple optical fibers inone or more rows. In certain embodiments, each connector 415A-415L,416A-416L terminates multiple transmit fibers and multiple correspondingreceive fibers to provide multiple links.

Further aspects of the disclosure relate to a method for fabricating afiber optic cable assembly. A method comprises providing M groups of Noptical fibers in a first cable assembly section, with each group of theM groups of N optical fibers including ordered optical fibers O1 to OXas members, wherein M≥4 and X≥4, such that a first group of the M groupsof N optical fibers includes ordered optical fibers O1 _(FIRST) toOX_(FIRST), and a last group of the M groups of N optical fibersincludes ordered optical fibers O1 _(LAST) to OX_(LAST). The methodfurther comprises, sequentially for each group of the M groups of Noptical fibers, inserting a segment of each ordered optical fiber into adifferent receiving area of a plurality of receiving areas of a fibersorting fixture to form a plurality of linear arrays of optical fibersincluding a different linear array of ordered optical fibers within eachreceiving area, wherein a first receiving area of the plurality ofreceiving areas receives optical fibers O1 _(FIRST) to O1 _(LAST) insequential order to form a first linear array of the plurality of lineararrays of optical fibers, and a last receiving area of the plurality ofreceiving areas receives optical fibers OX_(FIRST) to OX_(LAST) insequential order to form a last linear array of the plurality of lineararrays of optical fibers. The method additionally comprises, for eachlinear array of the plurality of linear arrays of optical fibers,separately fixing at least one segment of the linear array with anadhesion element to form encircled rollable fixed array of opticalfibers, and arranging the rollable fixed array of optical fibers in anon-linear position, thereby yielding a plurality of rollable,non-linearly positioned fixed arrays of optical fibers from theplurality of linear arrays of optical fibers. The method furthercomprises threading the plurality of rollable, non-linearly positionedfixed arrays of optical fibers through a plurality of second tubes asformative elements of a second cable assembly section including N groupsof M optical fibers. The method additionally comprises enclosing atransition between the M groups of N optical fibers of the first cableassembly section and the N groups of M optical fibers of the secondcable assembly section to form an integral fiber shuffle region of thefiber optic cable assembly.

Expanding on the preceding method, in certain embodiments the firstcable assembly section comprises a plurality of first tubes arrangedwithin a jacket, wherein each first tube within the jacket contains adifferent group of N optical fibers of the M groups of N optical fibers.In certain embodiments, each first tube of the plurality of first tubeincludes an end segment extending into the integral fiber shuffleregion. In certain embodiments, the integral fiber shuffle regioncomprises at least one of: (A) a length of no greater than 10 cm, or (B)a width no greater than a width of the jacket.

In certain embodiments, a method further comprises individuallyribbonizing a segment of each rollable fixed array of optical fibers ofthe plurality of rollable fixed arrays of optical fibers to form aplurality of ribbonized arrays of optical fibers. In certainembodiments, a method further comprises the plurality of ribbonizedarrays of optical fibers with a plurality of optical connectors(optionally embodied in a plurality of multi-fiber optical connectors).

In certain embodiments, a method further comprises terminating theplurality of ribbonized arrays of optical fibers with a plurality ofmulti-fiber optical connectors, wherein each multi-fiber opticalconnector of the plurality of multi-fiber optical connectors terminatesoptical fibers of at least two ribbonized arrays of optical fibers ofthe plurality of ribbonized arrays of optical fibers.

In certain embodiments, each adhesion element comprises a plasticallydeformable adhesion element, and the method further comprises, for eachrollable fixed array of optical fibers of the plurality of rollablefixed arrays of optical fibers, deforming the plastically deformableadhesion element and arranging the rollable fixed array of opticalfibers in a non-linear position before completing the threading of theplurality of rollable fixed arrays of optical fibers through theplurality of second tubes.

In certain embodiments, the threading of the plurality of rollable fixedarrays of optical fibers through the plurality of second tubes comprisesthreading two rollable fixed arrays of optical fibers through arespective second tube of the plurality of second tubes.

In certain embodiments, the forming of the integral fiber shuffle regioncomprises contacting exterior portions of the M groups of N opticalfibers and the N groups of M optical fibers with encapsulant material.In certain embodiments, the first cable assembly section comprisesstrength members of fibrous or string-like material, and the forming ofthe integral fiber shuffle region further comprises contacting endportions of the strength members with the encapsulant material. Incertain embodiments, a method further comprises supplying theencapsulant material to the integral fiber shuffle region in liquidform, followed by curing or otherwise solidifying the encapsulantmaterial to form a solid encapsulant.

Aspects of the disclosure may also be understood by review of thefollowing Examples.

Example 1: Compact 288 Fiber Shuffle Based on Ribbon Cable

Optical fiber ribbons emanating from a cable are pre-arranged into twostacked groups according to the arrangement shown in FIG. 12, eachhaving twelve ribbons with twelve optical fibers per ribbon. One of theoptical fiber ribbon groups comprises only transmit fibers and the otheroptical fiber ribbon group comprises only receive fibers.

Use of a ribbon stack lends itself to mesh connectivity, utilizing stepsof separating fibers from the ribbons, sequentially sorting fibers bycolor using sorting fixtures as disclosed herein (e.g., in FIG. 13), andre-ribbonizing fibers of the same color. In practice, a stack of twelveoptical fiber ribbons may be aligned and mounted in a fixture.Individual optical fibers may be separated from the optical fiberribbons and stacked sequentially into fiber receiving areas of fiberholders associated with fiber sorting fixtures as illustrated in FIG.13. In one embodiment the sorted (i.e., “shuffled”) optical fiber ineach fiber receiving area form a group and are ribbonized usingthermoplastic polymer. The ribbonizing process generates a ribbon thatappears glossy on one side and matte on the other side, thus allowingfor polarity identification even though all the fibers in the ribbonhave the same color. The shuffled transmit ribbons are marked todistinguish those from the shuffled receive ribbons. FIG. 11 shows are-ribbonized shuffle, where the transition from a first cable assemblysection (i.e., a normal optical fiber ribbon stack) to a second cableassembly section (i.e., a shuffled optical fiber ribbon stack) is lessthan 2 cm long.

Example 2: Compact 288 Fiber Shuffle Based on Distribution Cable

In another embodiment, a 384 fiber super trunk is downgraded to 288fibers by using only 12 of the 16 sub-units. The cable is oriented sothat the first sub-unit (e.g., first round fanout tube) is at the lowerposition. The shuffling process starts sequentially according to thesub-unit number. The jacket is removed, and optical fibers are sortedinto fiber receiving areas of fiber holders of two fiber sortingfixtures according to exterior colors and ring marks on the fibers into24 groups, as shown in FIG. 13. The fibers may be re-ribbonized usingthe method described in Example 1. The sorted fiber group in each fiberreceiving area is rollably fixed using a plastically deformable adhesionelement such as copper foil tape as described previously herein, andarranged in a non-linear position (e.g., folded into an unfoldablebundle). Two rollable, non-linearly positioned fixed (e.g., bundled)arrays of optical fibers with the same color (with one set having ringmarks) are fed into a round fanout tube, as illustrated in FIGS.15A-15B. The rollable, non-linearly positioned fixed arrays of opticalfibers exiting the fanout tube are unfolded or otherwise returned intothe original shape of a linear fiber array, with the fiber sequencebeing preserved for subsequent termination. FIG. 16 shows the resultingfiber shuffle region arranged in a tubular body serving as a furcationto house the optical shuffle and end segments of the tubes. A length ofthe shuffle region is about 50 mm, which provides sufficient length forthe fibers to be shuffled without micro-bends. The tubular body can befilled with encapsulant material (e.g., adhesive) similar to furcationplugs.

Technical benefits that may be provided by embodiments disclosed hereininclude one or more of the following: reduced cost and volumerequirements for making optical cross-connections in leaf-spinenetworks; enhanced ease and speed in making optical cross-connections inleaf-spine networks; and reduced optical insertion loss by eliminationof interconnects associated with conventional shuffle boxes.

Those skilled in the art will appreciate that various modifications andvariations can be made without departing from the spirit or scope of theinvention. Since modifications, combinations, sub-combinations, andvariations of the disclosed embodiments incorporating the spirit andsubstance of the invention may occur to persons skilled in the art, theinvention should be construed to include everything within the scope ofthe appended claims and their equivalents. The claims as set forth beloware incorporated into and constitute part of this detailed description.

It will also be apparent to those skilled in the art that unlessotherwise expressly stated, it is in no way intended that any method inthis disclosure be construed as requiring that its steps be performed ina specific order. Accordingly, where a method claim below does notactually recite an order to be followed by its steps or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is no way intended thatany particular order be inferred.

What is claimed is:
 1. A method for fabricating a fiber optic cableassembly, the method comprising: providing M groups of N optical fibersin a first cable assembly section, with each group of the M groups of Noptical fibers including ordered optical fibers O1 to OX as members, andwherein M≥4 and X≥4, such that a first group of the M groups of Noptical fibers includes ordered optical fibers O1 _(FIRST) toOX_(FIRST), and a last group of the M groups of N optical fibersincludes ordered optical fibers O1 _(LAST) to OX_(LAST); sequentiallyfor each group of the M groups of N optical fibers, inserting a segmentof each ordered optical fiber into a different receiving area of aplurality of receiving areas of a fiber sorting fixture to form aplurality of linear arrays of optical fibers including a differentlinear array of ordered optical fibers within each receiving area,wherein a first receiving area of the plurality of receiving areasreceives optical fibers O1 _(FIRST) to O1 _(LAST) in sequential order toform a first linear array of the plurality of linear arrays of opticalfibers, and a last receiving area of the plurality of receiving areasreceives optical fibers OX_(FIRST) to OX_(LAST) in sequential order toform a last linear array of the plurality of linear arrays of opticalfibers; for each linear array of the plurality of linear arrays ofoptical fibers, separately fixing at least one segment of the lineararray with an adhesion element to form a rollable fixed array of opticalfibers, and arranging the rollable fixed array of optical fibers in anon-linear position, thereby yielding a plurality of rollable,non-linearly positioned fixed arrays of optical fibers from theplurality of linear arrays of optical fibers; threading the plurality ofrollable, non-linearly positioned fixed arrays of optical fibers througha plurality of second tubes as formative elements of a second cableassembly section including N groups of M optical fibers; and enclosing atransition between the M groups of N optical fibers of the first cableassembly section and the N groups of M optical fibers of the secondcable assembly section to form an integral fiber shuffle region of thefiber optic cable assembly.
 2. The method of claim 1, wherein the firstcable assembly section comprises a plurality of first tubes arrangedwithin a jacket, wherein each first tube within the jacket contains adifferent group of N optical fibers of the M groups of N optical fibers.3. The method of claim 2, wherein each first tube of the plurality offirst tube includes an end segment extending into the integral fibershuffle region.
 4. The method of claim 1, wherein the integral fibershuffle region comprises at least one of: (A) a length of no greaterthan 10 cm, or (B) a width no greater than a width of the jacket.
 5. Themethod of claim 1, further comprising individually ribbonizing a segmentof each rollable fixed array of optical fibers of the plurality ofrollable fixed arrays of optical fibers to form a plurality ofribbonized arrays of optical fibers.
 6. The method of claim 5, furthercomprising terminating the plurality of ribbonized arrays of opticalfibers with a plurality of optical connectors.
 7. The method of claim 6,wherein the plurality of optical connectors comprises a plurality ofmulti-fiber optical connectors.
 8. The method of claim 5, furthercomprising terminating the plurality of ribbonized arrays of opticalfibers with a plurality of multi-fiber optical connectors, wherein eachmulti-fiber optical connector of the plurality of multi-fiber opticalconnectors terminates optical fibers of at least two ribbonized arraysof optical fibers of the plurality of ribbonized arrays of opticalfibers.
 9. The method of claim 1, wherein each adhesion elementcomprises a plastically deformable adhesion element, and the methodfurther comprises, for each rollable fixed array of optical fibers ofthe plurality of rollable fixed arrays of optical fibers, deforming theplastically deformable adhesion element and arranging the rollable fixedarray of optical fibers in a non-linear position before completing thethreading of the plurality of rollable fixed arrays of optical fibersthrough the plurality of second tubes.
 10. The method of claim 1,wherein the threading of the plurality of rollable, non-linearlypositioned fixed arrays of optical fibers through the plurality ofsecond tubes comprises threading two rollable, non-linearly positionedfixed arrays of optical fibers through a respective second tube of theplurality of second tubes.
 11. The method of claim 1, wherein theforming of the integral fiber shuffle region comprises contactingexterior portions of the M groups of N optical fibers and the N groupsof M optical fibers with encapsulant material.
 12. The method of claim11, wherein the first cable assembly section comprises strength membersof fibrous or string-like material, and the forming of the integralfiber shuffle region further comprises contacting end portions of thestrength members with the encapsulant material.
 13. The method of claim12, further comprising supplying the encapsulant material to theintegral fiber shuffle region in liquid form, followed by curing orotherwise solidifying the encapsulant material to form a solidencapsulant.